The objective of this program is to compare the sensitivity of three diagnostic radiopharmaceuticals Co57 Bleo, InIII Bleo and Ga67 Citrate in the four histologic types of bronchiogenic carcinoma. Preliminary reports indicate that radiolabeled Bleo has increased sensitivity in a wide variety of tumors. The present study will attempt to substantiate this claim by comparative scintillation scanning with the three compounds in 120 patients. Analysis of the radio Bleo and its metabolites in plasma and urine will be carried out to elucidate the mechanism of localization. The primary benefits of this study are earlier diagnosis, complete definition of extent of disease involvement and earlier treatment of these lung malignancies.